不同储藏条件下玉米微生物活性值与脂肪酸值相关性的分析

对不同储藏温度下高水分玉米微生物活性值与玉米主要品质指标脂肪酸值的变化及其相关性进行了分析。试验表明：随储藏温度及玉米水分含量的增加玉米微生物活性值与脂肪酸值呈上升趋势;当外界环境适合微生物生长繁殖时,相应的微生物活性值增加显著,由平均初始62u增加了12.15～25.28倍。分析显示,微生物活性值与玉米脂肪酸值的相关系数为0.7867～0.9923,两者相关性很好;微生物活性值与玉米脂肪酸值的相关性受储藏温度、玉米水分的共同影响,为此所建立的统计学模型为一个二元二次方程,其模型判定系数为0.9706,调整后判定系数为0.9608,说明模型拟合度很高。

抗乳腺癌候选药物活性值模型建立和分析

为了减少抗乳腺癌药物研发的时间和成本,建立化合物活性预测模型来筛选潜在活性化合物。首先对化合物进行预处理,选出前20个对生物活性值最具显著影响的分子描述符。其次借助遗传算法对BP神经网络的初始权值和阈值优化,最后根据MES值将优化前后的BP神经网络性能对比评估。优化前的MES值为0.22097,优化后的MES值为0.06923,神经网络模型性能提升明显,该模型可用于对化合物的生物活性值预测。

基于生物活性方法对红花注射液质量评价研究

目的:建立红花注射液生物活性的测定方法,对不同企业、批次的红花注射液生物质量进行评价。方法:采用浊度法测定体外血小板聚集率,从实验动物、诱导剂、血小板数量,重复性、中间精密度和重现性进行方法学验证,并测定不同企业、批次红花注射液的生物活性。结果:家兔和猫血浆对诱导剂ADP和COLL敏感,家兔PRP血小板数大于180×10~9/L,诱导剂所致最大血小板聚集率变化趋平、便于观察。重复性、中间精密度、重现性考察结果均为阳性(P<0.01)。ADP、COLL诱导的聚集抑制率,重复性考察RSD为3.72%、3.22%,中间精密度RSD为2.54%、1.64%,重现性考察RSD为5.56%和2.43%。14批红花注射液对ADP诱导的家兔血小板聚集呈阳性(P<0.05,P<0.01),聚集抑制率范围51.3%~83.7%;对COLL诱导的家兔血小板聚集呈阳性(P<0.01),聚集抑制率范围76.4%~88.2%。结论:体外血小板聚集测定方法操作简便,快速、经济,可准确测定红花注射液生物活性,评价不同企业、批次之间的质量差异。

基于镇静催眠作用的天麻超微粉生物活性限值测定方法研究

目的:基于天麻超微粉生物活性限值测定方法,建立其生物活性质量标准。方法:以给药剂量为考察因素,以天麻超微粉对小鼠自主活动的影响,以及对小鼠戊巴比妥钠诱导睡眠时间的影响为考察指标,建立天麻超微粉生物活性限值测定方法。结果:基于镇静催眠作用的天麻超微粉生物活性限值测定方法重复性、中间精密度、重现性均良好,方法适用性强。其中,天麻超微粉1.5g/kg对小鼠戊巴比妥钠诱导睡眠时间具有显著延长作用,天麻超微粉3g/kg对小鼠自主活动次数具有显著抑制作用。结论:基于镇静催眠作用的天麻超微粉生物活性限值测定方法可行性高,能有效配合传统检验方法对天麻微粉化制剂进行质量监控。

玉米储藏期霉菌活动及玉米主要品质变化研究

对两个玉米品种在不同水分条件下进行模拟储藏,定期测定玉米中脂肪酸、蛋白质的变化及微生物活动情况.结果表明:低水分玉米微生物代谢活动弱,水分含量15%以上的高水分玉米中微生物活性值在第10天开始明显上升,在50 d时,活性值高出低水分玉米10倍以上.储藏期玉米脂肪酸值呈上升趋势,水分越高,上升越快,水分含量15.4%的玉米脂肪酸值在第20天时上升趋势开始加快.水分含量15.4%的玉米水溶性蛋白含量在储藏期变化明显,而盐溶蛋白含量相对稳定,当水分含量升高至18%以上时,两种蛋白含量都会发生较大变化.低水分玉米中醇溶蛋白含量变化不大,而水分含量为18.5%的玉米在储藏20 d醇溶蛋的含量开始迅速下降,60 d后其含量下降了22%.

取代芳烃对月芽藻、大鼠等毒性的构效关系研究

提出了新的原子生物活性值(ai)并由其建构自相关拓扑指数(mL).0L和L分别与取代芳烃对月芽藻、发光菌慢性毒性关联,其相关系数分别为0.9315和0.9439;对酵母菌、发光菌、大鼠的急性毒性的相关系数依次为0.9482,0.9064和0.9762.

丁香提取液对储粮霉菌的抑制作用研究

丁香提取液原液对储粮中常见的灰绿曲霉、黄曲霉、青霉、黑根霉、高大毛霉有抑制作用,其抑菌圈直径分别为90 mm、90 mm、90 mm、30 mm、60 mm,最小抑菌浓度依次为0.391mg/mL、1.563 mg/mL、0.781 mg/mL、3.125 mg/mL、3.125 mg/mL.100 mg/mL丁香提取液以1%量添加于16.5%水分含量的玉米和16%水分含量的稻谷中,28℃下储藏16 d,其中微生物活性值分别为669 u和434 u,均明显低于空白组的2 684 u和2 437 u.丁香提取液防霉效果显著.

Rheological and Structural Properties of Sea Cucumber Stichopus japonicus During Heat Treatment

Changes in tissue structure, rheological properties and water content of raw and heated sea cucumber meat were studied. Sea cucumber Stichopus japonicus was heated at 25℃, 70℃ and 100℃ water for 5 min. The structural changes were observed using a light microscope and the rheological parameters （rupture strength, adhesive strength and deformation） determined using a texture meter. Microscopic photograph revealed that the structural change of heated meat was greater than that of raw meat. The rupture strength, adhesive strength and deformation of raw meat were smaller than those of the heated meat. Meanwhile, rheological parameters showed positive correlation with heating temperature. These changes are mainly caused by thermal denaturation and gelatinization of collagen during heating. These changes were also evidenced in observations using a light microscope and differential scanning calorimetry.

Synthesis,algal inhibition activities and QSAR studies of novel gramine compounds containing ester functional groups

2,5,6-Tribromo-l-methylgramine （TBG）, isolated from bryozoan Zoobotryon pellucidum was shown to be very efficient in preventing recruitment of larval settlement. In order to improve the compatibility of TBG and its analogues with other ingredients in antifouling paints, structural modification of TBG was focused mainly on halogen substitution and N-substitution. Two halogen-substitute gramines and their derivatives which contain ester functional groups at N-position of gramines were synthesized. Algal inhibition activities of the synthesized compounds against algae Nitzschia cIosterium were evaluated and the Median Effective Concentration （EC50） range was 1.06-6.74 lag ml^-1. Compounds that had a long chain ester group exhibited extremely high antifouling activity. Quantitive Structure Activity Relationship （QSAR） studies with multiple linear regression analysis were applied to fred correlation between different calculated molecular descriptors and biological activity of the synthesized compounds. The results show that the toxicity （log （I/EC50）） is correlated well with the partition coefficient log P. Thus, these products have potential function as antifouling agents.